The present teachings are predicated upon providing an improved heater and more preferably an improved heater for use in a vehicle. Generally, heaters include a wire that is formed in a pattern. The wire produces heat when electricity is applied to the wire. The wire may also be placed in a carbonaceous material so that as the wire heats up the heat is diffused into the carbonaceous material heating a larger area. However, achieving uniform heating in these devices may not always be achieved and hot spots may occur around the heating wires. Further, if a heating wire breaks the heater may cease to heat. Heaters may also include electrodes that are connected by a positive temperature coefficient material so that electricity is conducted from one electrode through the positive coefficient material to the other electrode and heat is produced. Other heaters have a woven configuration where a plurality of long materials are woven together to form a heater. These heaters may result in hot spots along one or more of the materials as these materials may allow for current drift along one wire.
In addition to heaters, sensors may be installed within a vehicle component. These sensors may be an occupant sensor that determines the presence of an occupant within a vehicle seat, the weight of the occupant, the size of the occupant, or a combination thereof so that, for example, an air bag may be turned on or off based upon sensed characteristics. Typically, when a heater and an occupant sensor are used, two discrete components are installed within a component so that one produces heat and the other senses. Having two discrete devices adds to the complexity of the system, increases installation expenses, increases the number of components that may fail, increases packing space, may cause electrical interference between the two devices, or a combination thereof. Therefore, it is desirable to have a combination heater that includes sensing capabilities so that the heater both heats and senses the presence of an occupant, the position of an occupant, or both.
Examples of heaters may be found in U.S. Pat. Nos. 5,824,996; 5,935,474; 6,057,530; 6,150,642; 6,172,344; 6,294,758; 7,053,344; 7,285,748; and 7,838,804; all of which are incorporated by reference herein for all purposes. Examples of combination sensors and heaters may be found in U.S. Pat. Nos. 5,006,421 and 7,500,536; and U.S. Patent Application Publication Nos. 2009/0255916; 2011/0290775; and 2013/0020305.
It would be attractive to have a combination heater and sensor that are free of discrete components. It would be attractive to have a heater that acts as a sensor without the addition of any additional sensing elements. What is needed is a flexible heater that provides good heating performance and also can be used as a sensor so that the heater/sensor may be installed in compact spaces, in spaces that require a high degree of flexibility, or both.